Marine boiler



G. B. TOWER.

MARINE BOILER. o. 251,747. Patented Jan. 3,1882.

j l g1 v UNITED STATES PATENT OFFIC GEORGE E. N. TOWER, OF BoSToN, MASSACHUSETTS, AssIeNoE, BY DIEEoT AND MESNE ASSIGNMENTS, T DAVID RENSHAW, OF OOHASSET, AND HARVEY T. LITOHFIELD, OF HULL, MAsSAcHUSETTS.

M-ARINE BOILER.

SPECIFICATION forming part of Letters Patent No. 251,747, dated January 3, 1882.

Application filed August 27. 1879.

To all whom t't may concern Be it known that I, GEORGE E. N. TowEE, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Marine Boilers, which improvements are fully set forth in the following specification and accompanying drawings.

My invention consists in an improved construction ofa marine boiler by which I gain advantages which are more fully described below.

In the drawings, Figure 1 shows a longitudinal section of my boiler on the line X X, and Fig. 2 a cross-section on the line 3 y.

I5 I construct my boiler with an outer shell, A,

and an inner shell, 13 and B, the space inclosed by the inner shell B containing the fireboxa'nd ash-pit, (the grate-bars beingindicated at a and the bridge-wall at b.) The space inclosed by the inner shell B is a flue extending through the boiler from the fire-box to the rear of the outer Shell. 111 the flue thus formed 1 place a large cylindrical tube, 0, and connect it with the shell B by small straight tubes 0, radiating from the cylinder 0, thus forming a flue of great strength to resist the expansive force of steam. By this construction that part of the boiler which incloses the fire-box is exposed to the direct action of the 0 fire, as is usual in such boilers, and the flame and smoke, after leaving the fire-box, pass through the flue around the cylinder G and between the radiant tubes c, the flue with its tubes and cylinder affording a large heatingsulface, the tendency of which is to draw the 5 Water from the bottom of the boiler through the lower tubes 0 into the cylinder 0 and to eject it through the upper tubes 0 into the,

upper part of the boiler, the water by this pro cess acquiring a rapid circulation and'being 4o acted upon by the fire throughout the whole'ot' its progress through the tubes and cylinder. This produces in the boiler the ebullition requisite for the rapid transformation of the water into steam at the water-line, which line should 5 be about where shown at d (I.

The cylinder 0 should be of sufficient size to be entered by a workman for the purpose of putting in the tubes or replacing any that may be injured. The shell B is of course accessible from the inside of the boiler.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

A marine boiler consisting of the outer shell, A, inner shell, B B, fire-box, and ash-pit, to which is connected the water-flue O, communicating with the water-space of the boiler bye. number of radiating water-tubes, c, all arranged substantially as shown, and for the purpose specified.

G. B. N. TOWERQ 

